The mostly harmless teeth staining was first observed in communities with high natural fluoridation.

牙齿氟斑病主要是无害的牙齿染色，最早自然高氟化物地区被观察到。

There is nothing on the fluoridation of water, and too little on nutrition.

书中也有饮水加氟法进行阐述，学方面也较少被提及。

The study authors found that prior to 1975, there was a clear and important effect on prevention of tooth decay in children due to water fluoridation.

研究作者发现， 1975 年之前，水氟化物儿童蛀牙的预防有明显且重要的效果。

Supporters of water fluoridation point to studies like this one that looked at what happened in Calgary, Canada, after they stopped fluoride in their water in 2011.

水氟化物支持者指出了像这样的研究，该研究观察了加拿大卡尔加里 2011 年停止水中添加氟化物后的情况。